Sheet material and manufacturing method and apparatus therefor

ABSTRACT

A method of manufacturing a single use processing substrate includes the step of extruding a first layer having ridges and troughs between the ridges. The method further includes the steps of placing a second layer into the troughs while the first layer is pliant and compressing the pliant ridges so that the second layer is bound into the troughs.

RELATED CASES

This application is a continuation-in-part of Ser. No. 10/075,020, filedFeb. 12, 2002 now U.S. Pat. No. 6,986,931, entitled “ProcessingSubstrate and/or Support Surface,” which is a continuation-in-part ofSer. No. 09/677,663, filed Oct. 2, 2000 now abandoned, entitled“Processing Substrate and/or Support Surface.”

TECHNICAL FIELD

The present invention relates generally to sheet materials, and, moreparticularly, to an in-line manufacturing method and apparatus forproducing such sheet materials.

BACKGROUND ART

Management of bacteria, liquids, fats and other waste during thepreparation and handling of foods is of concern in food handling areas.Typically, such areas include the kitchen, although modern lifestylesinclude out-of-home occasions such as social and recreational gatheringswhere food is prepared, transported and/or served outside of thekitchen. Foods of particular concern from the standpoint of possibilityof food-borne illness are fish, fowl and ground meats; although allfoods present some degree of risk. Current media articles discuss thefact that the common cutting boards used in the preparation of foods area source of food contamination. Other commonly used food preparationsurfaces, such as countertops, also present some risk. Specifically, ithas been found that bacteria can become entrapped in irregularities ofthe cutting surface, resulting in a surface that is difficult, if notimpossible, to clean and/or sterilize. The cutting surface thus becomescapable of transferring bacteria to other foods, which provides afavorable media for pathogens to proliferate, resulting in an increasedpotential for food-borne illness, particularly when contact is had withhigh-risk foods. In fact, even some foods considered to bepathogenically low-risk, such as fresh fruits and vegetables can becomecontaminated, waiting for the right environment for the bacteria toproliferate. Illnesses from mild to severe or even fatal can result.

Another issue with cutting boards is the transfer of juices from thecutting board to other surfaces in the kitchen due to the fact that thecutting board is normally not designed to capture and contain juicesduring the cutting operation and thereafter through final disposal. Inaddition to the inconvenience of having to clean the countertop or othersurface(s) exposed to the juices, a possibility exists that other fooditems placed on such surface(s) may be cross-contaminated.

Products are in the marketplace today that attempt to address issues ofliquid, fat, and bacteria management during cutting and general foodpreparation. However, these products fall short of optimum in one way oranother. Specifically, they do not absorb, are not cut resistant, and/orfail to provide an effective bacteria barrier between the food beinghandled and the work surface. Also, bacteria are retained which cancause contamination during subsequent use.

In addition to the foregoing, most, if not all, food preparationsurfaces lack one or more of the following attributes:

-   -   1. a single use, disposable cutting surface that is virtually        cut resistant and also entraps and holds waste and bacteria;    -   2. a food preparation surface which prevents food movement        during cutting;    -   3. a food preparation surface which prevents and/or selectively        manages movement thereof on the counter top during cutting;    -   4. a single-use food preparation surface which is easily        disposed of while securely containing contaminants; and    -   5. a single-use cutting surface that lays flat during use.

Palmer U.S. Pat. No. 3,194,856 discloses a continuous process ofcreating decorative effects in a linoleum surface covering. Granules oflinoleum composition are deposited upon a linoleum composition basesheet. The mass is then passed between calendar rolls, resulting in adecorative sheet having the granules embedded in the surface of thesheet without substantial distortion of the granules.

Kennette et al. U.S. Pat. No. 4,035,217 discloses a method ofmanufacturing absorbent facing materials. Fiberwood pulp laminate isformed by depositing wood pulp on one side of a cellulosic textile fiberweb. The laminate is then confined between a pair of moving surfacesand, while confined, the laminate is saturated with water. Resin bindermaterial is thereafter deposited on the web side of the wet laminate.The laminate with the resin thereon is dried to remove the water andcure the binder to produce the absorbent facing material.

Nishino et al. U.S. Pat. No. 5,620,712 discloses a method and apparatusfor continuously making the top-sheet of a fluid absorptive article. Thetop-sheet comprises a first sheet, having a skin-contacting area andliquid passages. Molten fibers arc blown against the lower side of thefirst sheet to form a second sheet made of melt-blown non-woven fabric.The second sheet is thereby welded to the first sheet around loweropenings of the liquid passages.

Hoopman et al. U.S. Pat. No. 5,681,217 discloses a method for making anabrasive article. An abrasive slurry is coated into cavities of aproduction tool. The production tool then contacts a front surface of abacking material such that the abrasive slurry wets the surface of thebacking material. An energy source is then used to cure a binder in theabrasive slurry, which converts the abrasive slurry into a plurality ofabrasive composites bonded to the backing material.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, a method ofmanufacturing a single use processing substrate includes the step ofextruding a first layer having ridges and troughs between the ridges.The method further includes the steps of placing a second layer into thetroughs while the first layer is pliant and compressing the pliantridges so that the second layer is bound into the troughs.

In accordance with another aspect of the present invention, an apparatusfor production of a single use processing substrate comprises a firstmeans for extruding a first layer having ridges and troughs between theridges. The apparatus further comprises a second means for placing asecond layer into the troughs while the first layer is pliant and athird means for compressing the pliant ridges so that the second layeris bound into the troughs.

In accordance with yet another aspect of the present invention, a sheetmaterial comprises a first cut resistant layer having a plurality ofprojections extending away from troughs disposed between theprojections. The sheet material further comprises a second layer ofabsorbent material disposed in the troughs and captured therein byoverhanging portions of the projections.

Other aspects and advantages of the present invention will becomeapparent upon consideration of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A comprises an isometric view of a processing substrate accordingto one embodiment;

FIG. 1B comprises an isometric view of a processing substrate accordingto another embodiment;

FIG. 2 comprises a side elevational view of the processing substrate ofFIG. 1;

FIG. 3 comprises a sectional view taken generally along the lines 3—3 ofFIG. 1;

FIG. 4 comprises a perspective view of apparatus for producingprocessing substrates as shown in FIG. 1A;

FIG. 5 comprises an isometric view of a processing substrate accordingto another embodiment;

FIG. 6 and FIG. 6A comprises an isometric view of a processing substrateaccording to another embodiment;

FIG. 7 comprises a cross sectional view of FIG. 6;

FIG. 8 comprises an isometric view of a processing substrate accordingto another embodiment;

FIG. 9 comprises an isometric rear view of a processing substrateaccording to FIG. 8;

FIGS. 10–13 comprise plan views of processing substrates according toother embodiments;

FIGS. 14 and 15 comprise isometric views of processing substrates n rollform;

FIGS. 16–19 comprise cross sectional views of processing substratesaccording to other embodiments;

FIG. 20 comprises an elevational view of a processing substrateaccording to another embodiment;

FIG. 21 comprises a cross sectional view of a processing substrateaccording to another embodiment;

FIGS. 22 and 23 comprise isometric views of apparatus for producingprocessing substrates according to further embodiments;

FIG. 24 comprises a cross sectional view of a processing substrateaccording to another embodiment;

FIG. 25 comprises a plan view of the absorbent ply of the top layer of aprocessing substrate according to a further embodiment;

FIG. 26 comprises a plan view of the absorbent ply of the top layer of aprocessing substrate according to another embodiment;

FIG. 27 comprises an isometric view of an apparatus for producing aprocessing substrate as shown in FIG. 25;

FIG. 28 comprises an isometric view of another apparatus for producing aprocessing substrate as shown in FIG. 25;

FIG. 29 comprises a plan view of a processing substrate according to afurther embodiment;

FIG. 30 comprises a sectional view of a first embodiment of theprocessing substrate of FIG. 30 along the lines 30—30;

FIG. 31 comprises a sectional view of a second embodiment of theprocessing substrate of FIG. 30 along the lines 30—30;

FIG. 32 comprises a plan view of a processing substrate according toanother embodiment;

FIG. 33 comprises a sectional view of the processing substrate of FIG.32 along the lines 33—33;

FIG. 34 comprises a perspective view of an apparatus for producing theprocessing substrates of FIGS. 29–33; and

FIG. 35 comprises an isometric view of an apparatus for producing sheetmaterial according to a further embodiment of the present invention; and

FIGS. 36–38 are sectional views of the sheet material of FIG. 35 alongthe lines 36—36, 37—37, and 38—38, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1A, a processing substrate and/or support surfacethat may be used as a food preparation surface or sheet 10 preferably isplanar (i.e., flat) in shape. Alternatively, as seen in FIGS. 1B and 2,the sheet 10 may be tray-shaped and includes a substantially planarcentral portion or base 12 and inclined or curved side surfaces 14 a–14d, wherein the base 12 and side surfaces 14 together define a generallyconcave structure. The side surfaces 14 may be formed by folding and/orscoring the sheet 10 at corner portions 15 a–15 d and optionally foldingor scoring the sheet 10 at portions 13 a–13 d intermediate the base 12and side surfaces 14. The inclined or curved side surfaces 14 couldalternatively be formed by any other process, such as forming throughthe application of heat, vacuum forming, vacuum pressure forming, or thelike. If desired, fewer than four inclined side surfaces 14 may beprovided. For example, only the inclined side surfaces 14 a–14 c may beemployed to provide a flat edge surface that may be oriented toward theuser so that an inclined side surface does not interfere with the user'shands or arms. Preferably, although not necessarily, the sheet 10 isintended for one time use as a cutting surface or as a sheet supportingan article or as a barrier for isolating an article resting on a surface(for example, a plant on a shelf, an article of food on a counter or ina microwave, or the like), or as a food preparation and bacteriamanagement sheet. Following the use the sheet 10 and any waste productsand contaminants carried thereby may be disposed of in any suitablefashion. The concave or tray-shaped structure (if used) facilitatesretention of the waste products and contaminants during the foodpreparation, transport and/or disposal processes. Additionally oralternatively, the sheet 10 may be sufficiently flexible to allow theuser to bend and/or fold the sheet 10 to prevent escape of wasteproducts and contaminants therefrom during disposal.

Referring also to FIG. 3, according to one embodiment, the sheet 10 alsoincludes a cut-resistant, liquid-permeable top or upper portion or layer16, which substantially prevents the integrity of the sheet 10 as awhole (and, in particular, the layer 16) from being compromised duringcutting while at the same time allowing passage of juices and liquidsthrough the layer 16. Preferably, the upper portion or layer 16 is madeof a material sufficiently durable to withstand aggressive cutting ofmeats, vegetables and other food items by a serrated or non-serratedblade, particularly in the situation where a cutting motion is appliedto meats, poultry or fish (or any other fibrous protein material) thatresults in the application of cutting force components in multipledirections to the item. A serrated blade presents a series of equally ornon-equally spaced points or tips to the upper surface of the layer 16that can snag or otherwise catch on edges of the material used for thetop layer 16. Because of this it is generally preferred (although notnecessarily the case) that the top layer 16 have irregularly or randomlyspaced openings therein that prevent any points or tips from contactingmaterial below the layer 16 during cutting. In this way, the possibilitythat the integrity of the sheet 10 would be compromised is reduced.

In addition to the foregoing, the upper portion or layer 16 preferablyhas an upper surface 17 that is textured or otherwise formed to preventslippage of items thereon during processing.

The sheet 10 further includes a middle or intermediate portion or layer18 that may be made of a liquid absorbent material that retains thejuices and liquids passed by the upper layer 16, as well as a bottomportion or layer 20, which is preferably made of a slip-resistant,liquid, and bacteria impervious material to prevent slipping of thesheet 10 and leakage of liquids and transfer of bacteria onto or from awork surface (such as a countertop, a cutting board, or the like) duringuse.

The upper layer 16 may be of a length and width substantially equal tothe length and width of the middle layer 18. Alternatively, the upperlayer may be of a smaller size than the size of the layer 18, therebyproviding a cutting surface that is partially or fully surrounded byportions of the middle layer 18. As a further alternative, the top andbottom layers 16, 20 may be of the same size and the middle layer may beof a smaller size and so arranged relative to the layers 16 and 20 suchthat the middle layer 18 is surrounded by the joined outer margins ofthe layers 16 and 20.

If desired, the sheet 10 may instead include a different number oflayers or portions each imparting one or more desired characteristic(s)to the sheet 10. In addition, the sheet 10 may comprise a single layeror portion or multiple layers or portions wherein each layer or portionis made of material that is differentially treated during production toobtain multiple desired characteristics. Still further, the sheet 10 mayinclude one or more layers or portions that are not differentiallytreated during production in combination with one or more layers thatare differentially treated during production. For example, the sheet 10could comprise a single layer that is liquid absorbent, but which has afirst surface that is treated (by any suitable process, such as theapplication of heat or a chemical additive) during production to producea cut-resistant, liquid-permeable surface. The sheet 10 may further havea second surface opposite the first surface that may be treated by anysuitable process (for example, as noted above) during production toproduce a slip-resistant barrier surface. Alternatively, the sheet 10could comprise two layers, a first of which provides a slip-resistantbarrier surface, and a second of which provides a cut-resistant surface.In this case, the liquid absorbent layer may be omitted, or theliquid-absorbent material may be provided as part of one of the first orsecond layers or as a separate layer. Still further, the slip-resistantsurface and/or the cut-resistant, liquid-permeable surface could beomitted, if desired.

The various layers 16, 18 and 20 are secured or formed together in anysuitable fashion taking the various materials of the layers intoaccount. For example, two or more of the layers 16, 18, and 20 may beheated to fuse the layers together or the layers may be laminated aspart of an extrusion process. Two or more of the layers could instead besecured together by an adhesive including a hot melt adhesive as well asa solvent or water based adhesive, as long as the adhesive is approvedfor food contact and compatible with the layers. Alternatively, two ormore of the layers 16, 18, and 20 may be formed using materials and/or amanufacturing process which result in simultaneous formation and bondingof such layers. Still further, the layer 16 may be bonded or otherwisesecured to the layer 20 at selected locations, thereby capturing thelayer 18 therebetween. In this case, the layer 18 may have one or morevoids therein to facilitate the joinder of the layers 16 and 20 at thelocation(s) of the void(s). Still further, the layer 18 may be omittedand the layers 16 and 20 may be joined at spaced locations to createvoids between the layers 16, 20 which serve to attract and retainliquid(s) therein by capillary action.

FIG. 4 illustrates an apparatus that may be used to produce a number ofcutting surfaces as shown in FIG. 1A. An extrusion die or other deliverydevice 40 deposits thin streams of molten thermoplastic onto a web 42 ofliquid-absorbent material, such as cellulosic tissue or batting. Thematerial deposited on the web 42 is chosen from but not limited topolyolefins, such as polyethylene (PE), polyolefin metallocenes,metallocene polypropylene (mPP) or polypropylene (PP) includinghomopolymers and copolymers thereof, polyester, such as polyethyleneterephthalate (PET), polystyrene (PS), polyvinyl alcohol (PVA),polyvinyl chloride (PVC), nylon (such as nylon 6 or nylon 66),polyacrylonitrile (PAN), acrylonirile-butadiene-styrene (ABS),ethylene-vinyl acetate (EVA) copolymer, multi layers of the same ordifferent polymers, blends and recycled polymers (including polymersthat are cured by ultraviolet or visible light, an electron beam, wateror other curing agent). Addition of one or more filler(s) may beadvantageous both from a cost advantage as well as improvement ofmodulus, heat distortion and cut resistance. Preferably, each stream isapproximately on the order of 1–100 thousandths inch (0.0254 mm–2.54 mm)wide and are deposited at equally-spaced locations on the web 42approximately 1–500 (0.025 mm–12.7 mm) thousandths inch apart.Alternatively, the streams may be deposited at non-equally spacedlocations on the web 42 and/or may be of differing widths and/or may bedeposited at different points of time. Still further, different streamshapes (e.g., a wavy, curved, discontinuous or interrupted stream asopposed to the linear continuous stream extent described above and/or adifferent cross-sectional shape) and/or different materials could besequentially deposited on the web 42. In other words, a single streammay comprise a first portion of a first material, a second portiondeposited after the first portion of a second material, a third portiondeposited after the second portion of a third material or the firstmaterial, etc. In an alternative embodiment, adjacent streams may be ofdiffering materials. In a general sense, N different materials may bedeposited or otherwise formed in situ on the web 42 in a repeating ornon-repeating sequence or pattern or in a random fashion. In the case ofa repeating sequence or pattern, the repetition frequency may beestablished at a value less than or equal to N. In any event, the choiceof materials, sequence or pattern, and the like affect the physicalcharacteristics of the resulting surface.

If the upper layer 16 is to be smaller than the size of the layer 18,then the streams are deposited only on a center portion of the web 42.In addition, the flow of thermoplastic resin is periodically interruptedso that discrete portions of web are formed having thermoplastic thereonwherein such portions are separated by further web portions not havingthermoplastic deposited thereon. The web 42 then passes between a pairof rolls 44 a, 44 b. Preferably, the roll 44 a is smooth and the roll 44b has a plurality of diamond-shaped or other shaped protrusions 46 onthe surface thereof. The protrusions 46 deform and spread out the stillmolten thermoplastic streams to transform the linear streams into adesired two or three dimensional pattern of thermoplastic resin on theweb 42. The web 42 then passes between one or more additional pairs ofrolls 48 that further spread out and/or flatten the thermoplasticstreams and impart a desired texture thereto. The resulting surfaceprovides cut resistance and prevents food from sliding thereon Ifdesired, any pattern can be created on the web 42, for example, a randompattern or a crisscross pattern could be created by drizzling, sprayingor otherwise applying the material thereto.

Thereafter, the web 42 is inverted (i.e., turned over) and the layer 20is formed in situ by lamination or other delivery of a thermoplastic orother material onto an undersurface 50 by an extrusion die or otherdelivery apparatus. The layer 20 may alternatively be formed withoutfirst inverting the web 42 by any suitable process. The layer 20 may beformed of any of the materials described above in connection with thelayer 16 including polyolefins such as PE or PP, polyesters such as PET,PS, PVA, PVC, nylon, PAN, ABS, EVA, etc. . . . In alternativeembodiments, a suitable coating material may be applied by a sprayer andmechanically processed by a doctor blade or a portion of the material ofthe layer 18 may be melted or otherwise differentially processed asnoted above so that a sealed portion is obtained (if the material of thelayer 18 so permits). Still further, a barrier layer of TYVEK® (sold byE. I. Du Pont de Nemours and Company of Wilmington, Del.) mayalternatively be secured to the underside of the web 42 by any suitablemeans.

The layer 20 may be formed with a pattern or texture by embossing and/ormay be coated or laminated or otherwise formed with a slip-controlling(such as slip resistant) or adhesive material. The slip control may beprovided by a continuous or discontinuous surface of the layer 20, asdesired. The resulting coated web is then cut at appropriate locationsto form the cutting sheets.

The processing substrate as described herein is not limited to theconcept of utilizing disposable, absorbent barrier surfaces in place ofconventional cutting boards, but encompasses all food handling andarticle support occasions where absorbent, liquid/bacteria barriermanagement is desirable. The processing substrate can have arrangementsof various barriers, absorbent and cut/physical abuse resistantmechanisms for the management by containment or isolation of wastes andbacteria encountered during food processing, such as cutting, drainingand accumulating (staging). All of these processes involve the use of agenerally horizontal work surface, where the embodiments herein may beadvantageously employed. In general, of the processing substrate mayinclude N layers or other portions which may be arranged in a suitableor desired fashion to obtain the desired mechanical, absorbent, barrier,and/or other characteristics.

A preferred embodiment utilizes the cut resistant layer 16 as the toplayer, where the cutting operation is performed. If desired, the layer16 may be omitted and the cut-resistant surface could instead beprovided as part of the bottom layer 20. In this case the cut-resistantsurface would need to be impervious to liquid and the material of themiddle layer 18 could be exposed directly to the item being cut. Thisalternative may result in the possibility of material transfer from thelayer 18 to the food, although such possibility can be minimized throughcareful control of materials and design. For example, in an embodimentwhere the liquid absorbent layer 18 is the top layer, effort should bemade to ensure minimum transfer of material (e.g., fibers) to the foodbeing cut. In the case of paper, woven or nonwoven fabrics as thematerial of the liquid absorbent layer 18, thermal bonding of fiber tofiber in such layer and/or fiber of such layer to the material of thebottom layer 20 significantly reduces fiber transfer to the food. Manyother commercially available techniques for minimizing transfer ofmaterial(s) exist. For example, various thermal embossing patterns couldbe used. Care should be taken to ensure that the absorptive capacity ofthe material of the layer 18 is minimally affected by the mode ofbonding.

Other arrangements can be envisioned, such as thermoplastic/cellulosicconglomerates or agglomerates. In these arrangements thermoplastic andcellulosic absorptive materials are compressed together or otherwiseprocessed and/or combined to form a cut resistant, absorptive sheet.When a thermoplastic liquid barrier component is fused on one side, acut resistant, absorptive, barrier system is formed.

Still further, each layer or portion may be “tuned” (in other words, thematerial selection, properties and/or amounts may be controlled) toobtain the desired attributes and properties for each. For example, afirst sheet could be designed for cutting chicken comprising an upperlayer of PE or PP, a middle layer of cellulosic absorbent material and abarrier layer of polymeric material as described above in connectionwith FIG. 4. A second sheet could alternatively be envisioned for lightfood preparation (such as assembling sandwiches from pre-cut foods)including the same three layers in different proportions. This mightcomprise an upper layer of PE or PP having a thickness substantiallyless than the thickness of the upper layer of the first sheet, a middlelayer of cellulosic absorbent material identical to the material of themiddle layer of the first sheet and a barrier layer of polymericmaterial identical to the material of the barrier layer of the firstsheet. The thicknesses of the middle and barrier layers of the secondsheet may be different than or identical to the thicknesses of the samelayers of the first sheet. This provides a sheet having lesser cutresistance than the first sheet, but still provides a sheet having thedesired absorbency and barrier characteristics appropriate to theintended application for the sheet. Still further, the cellulosicmaterial of the middle layer might be replaced by a more oleophilicmaterial, such as nonwoven polypropylene or the same or a differentcellulosic material that has been treated to increase the oleophilicproperties thereof, to form a sheet for managing oil during foodpreparation.

Any of the embodiments disclosed herein provide a processing and/orsupport surface that retains liquids yet is convenient and spaceeffective for easy disposal. The product may be pre-treated forpackaging purposes and/or to allow easy and convenient disposal.Examples of pretreatment for easy disposal include pleating, folding,scoring, forming and the like.

As noted above, the cut resistant top layer 16 may be made from a randomor regular pattern of thermally formable material or coating materials.In addition to the examples given above, the material of the layer 16may comprise latexes, epoxies, paper coating and a contact drum printthat is treated by a doctor blade. Still further, a continuous sheet ofpolymer film could alternatively be used in place of the cut-resistantupper layer described in conjunction with FIG. 4, wherein the film isperforated by any suitable process, such as vacuum, needle or water jetperforating, laser, hot pins or mechanical punching to create holes forthe passage of liquid therethrough. A minimum hole diameter of betweenabout 0.060 and about 0.125 thousandths inch (0.003175 mm–0.001524 mm)is preferred. Less than 8 holes/square inch (depending upon holesize(s)) is preferred. The spacing between the tips of serrated knifeblades vary; however, the smaller the hole diameter, the less the chancethat a tip of such a blade will catch on an edge of a hole. The film canbe made of virgin polymer or blends of virgin and recycled materials orfrom recycled materials alone. As noted above, fillers or pigments toincrease opacity, optimize desired properties, and/or reduce cost areoptions. Alternatively, porosity can be achieved using differentprocesses such as pre- or post-lamination, lost mass process, leachingor scavenging.

The cut resistant layer 16 can alternatively comprise other cutresistant structures, such as netting, fabrics or scrims, so long as thelayer allows easy passage of juices and other liquids through to theabsorbent layer 18. In each embodiment, the minimum thickness for thelayer 16 is approximately 5 mils (0.127 mm) for unfilled materials, butit may be possible to achieve adequate cut resistance with thinnerarrangements.

Care should be taken to use food contact approved materials. The use ofa discontinuous layer affords a cut resistant barrier that keeps thematerial of the layer 18 from the surface of the item being cut. Also,the discontinuous layer lends itself to being easily disposed of due toease of “wadding” by the user The liquid-absorbent layer 18 preferablyis an absorbent structure selected from, but not limited to: non-wovenfabrics of synthetic polymers or blends of fibers; laminates of variousfabrics or combination of fabrics; cellulosic material(s), meltblown andspunbonded nonwoven fabrics, woven fabrics, multiple layers andcombinations of fabrics and papers, absorbent powders like polyacrylicacid polymers, open-celled foams, perforated closed cell foams and/orblends of polymer and cellulosic materials. The layer 18 couldalternatively comprise any other suitably absorbent commerciallyavailable materials.

If a synthetic polymer fabric, woven or nonwoven, is used for the layer18, a food-contact approved wetting agent or other surface additive maybe required to ensure water wettability of the fabric. Typical levelsare <1% by weight of the fabric. Some hydrophilic fibers can be used forlayer 18 in blends with synthetic polymers to eliminate the need forsurfactants. Examples of these hydrophilic fibers are cellulose, rayonand PVA; however, the applications herein are not limited to thesehydrophilic fibers. In some cases, lamination of two different fabricsmay be necessary to obtain sufficient hydrophilic properties. However,it is preferred in this example, to use a blend of fibers in one fabric.Typically, a minimum of 5 to 10% hydrophilic fiber is needed in a fiberblend to ensure that the fabric has sufficient hydrophilic properties.An additional benefit of using fiber blends in the layer 18 is thepossibility to use different polymers in the layer 16 and still employthermal bonding of the layers.

The bottom layer 20 forms a barrier to prevent liquids from theabsorbent layer 18 from passing through to the surface of the countertop or other support surface. The bottom layer 20 also blocks thetransfer of bacteria between the layers 16 and 18 and the surfacesupporting the sheet 10. The bottom layer 20 can be any substratematerial that prevents passage of liquid therethrough. For example, thelayer 20 may comprise a continuous sheet of PP or PE film (or any otherpolymer film, such as those noted above) having a thickness on the orderof 0.25–5.0 mils (0.00635–0.127 mm), although a different thicknesscould be used instead. Fillers and/or coloring agents or other additivescan be utilized to obtain the desired characteristics, color and/oropacity. Like the layer 16, the film can be made of virgin polymer orblends of virgin and recycled materials or from recycled materialsalone. Typically, the layer 20 is fabricated of materials chosen from agroup of materials that will thermally bond to the layer adjacentthereto (in the preferred embodiment the layer 18), thereby obviatingthe need for adhesives, which are costly and can adversely affect thedesired characteristic (e.g., the absorbent nature) of the adjacentlayer.

In summary, the embodiments discussed herein comprehend any structure(single layer or multilayer, conglomerates, agglomerates, foams, productsuspended in one or more matrices or suspensions) having cut resistantproperties, liquid-absorbent properties and/or barrier properties. Theproperties may be afforded by any suitable processing technique(s), suchas coating or other application of product, denaturing or other changein a material (whether by flame treating or other application of heat,chemicals, irradiation, UV, IR or visible light, etc . . . ), mechanicalor electrical processing, or the like. In addition, the variousmaterials may be selected from ecologically advantageous materials thatbiodegrade.

In the case of foams, these can be either of the open-cell or closedcell type made from conventional polyolefins or polyolefin filledmaterials. Still further, a foam can be filled with combinations of anyof the non-conventional materials listed below, such as egg whites andshells or other foams could be used with fillers like mica, starch, woodflour, calcium carbonate, and flax. Other suitable materials may bebread impregnated with adhesive binders, foamed potato starch orpolyvinyl acetate with any number of fillers like ground bone, lime ortalc. Other suitable foams are polyvinylpyrollidone aggregate open cellfoams and PE and PP aggregate foams. Such combined materials can providecut resistance and/or liquid absorption properties.

Hollow fibers could also be employed. In this case, hollow fibers of acritical diameter may be used to suck up and retain water by capillaryaction. These fibers could possess cut resistant properties as well asliquid management properties and a barrier layer could be secured by anysuitable means to a mat of such fibers to obtain a processing surface.

The following materials possess one or more of the above absorptiveproperties, cut resistance properties, and barrier properties effectiveto manage bacteria or liquids during the preparation of food.Accordingly, any of these materials can be used in the embodimentsherein. Some are very eco-effective in that they decompose directly tofood for biocycles and many do not absorb microwave energy and are safefor use as a support surface in microwave ovens:

-   -   “Earth shell” (a composition of potato starch and lime        manufactured and/or sold by E. Khashoggi Industries, LLC of        Santa Barbara, Calif.);    -   clay or clay-filled materials optionally reinforced with        materials such as ground corncobs, silica, irradiated waste        sludge or woven straw;    -   kelp and other marine vegetation;    -   ground marine shells (e.g., lobster, crab, shrimp or any other        exoskeletal creatures, oyster, clam, scallop or zebra mussel        shells) held together by a binder or matrix of any suitable        material, such as barnacle adhesive;    -   cork;    -   wood or wood product derivatives and veneers; natural fibers        like cotton or wool either woven or in non woven batts;    -   materials such as flour, silica, rice, rice kernel, rice germ or        starch of any kind (e.g., corn or potato starch) either alone or        held together by a binder such as polyvinyl acetate or held        together as conglomerate or agglomerate systems by any        appropriate material(s);    -   animal, insect and/or fish products including shells, skins,        hides, hooves, glues made from hides or hooves, scales or bones;    -   other protein glues or glues from other products (such as        gluten);    -   egg white or egg yolk composites with flour, rice, egg shells,        flours with yeast, corn starch or potato starch;    -   lecithin;    -   polymeric substances created from high temperature treatment, or        other breakdown, of carbon chains predominantly in sugars and        oils, such as is found in apples, grapes, cherries or other        fruit (skins and/or pulp), olives (skins and/or pulp), olive        oil, corn oil, vegetable oil, canola oil, or eggs;    -   bioengineered cell growth materials;    -   grasses and other terrestrial vegetation;    -   bark;    -   nonwoven microfibers;    -   cellular absorption swellable materials (such as Drytech® sold        by The Dow Chemical Company of Midland, Mich.);    -   molecular sieve materials (e.g., a desiccant); and    -   hydrophilic powders, like polyacrylic acid or the like.

Another embodiment can be seen in FIGS. 5–9. As seen in FIGS. 5–9, abilayer single use processing substrate comprises a first two-plycut-resistant layer 60 and a second two-ply layer 62. The first layer 60has a first surface area 64 and comprises a tissue ply 66 disposed belowa thermoplastic material ply 68. The tissue ply 66 has a thickness inthe range of between about 2 and about 6 mils (0.0508 mm–0.1524 mm) andthe thermoplastic material ply 68 has a thickness in the range ofbetween about 4 and about 8 mils (0.1016 mm–0.2032). The second layer 62has a second surface area 70 and comprises a tissue ply 72 disposedabove a thermoplastic material ply 74. The tissue ply 72 has a thicknessin the range of between about 2 and about 6 (0.0508 mm–0.1524 mm) milsand the thermoplastic material ply 74 has a thickness in the range ofbetween about 1 and about 5 mils (0.0254 mm–0.127 mm). The first layer60 is disposed atop the second layer 62 such that the first layer tissueply 66 and the second layer tissue ply 72 are secured to each other bysuch means as an adhesive or a water soluble polyethylene oxide coatingon first and second layer tissue plies 66, 72, and wherein a portion ofthe second surface area 70 is laterally disposed outside of the firstsurface area 64.

The adhesive (not shown) can be applied either to the entire surface ofthe first layer 60 or can be applied in any number of patterns,including without limitation interrupted patterns such as a series ofspaced spots and continuous patterns such as parallel stripes orinterlocking stripes. One preferred pattern is a series of parallelstripes. It has been found that this pattern adds a capillary effect tothe processing substrate by slightly separating the sheets. Thisseparation creates a capillary effect that helps draw liquids away fromthe surface of the cut resistant layer 60. Also, these parallel stripeschannel the liquid toward that portion of layer 62 that is not coveredby layer 60 in the preferred embodiment.

Each of the first and second layers 60, 62 can be produced by extrusioncoating the thermoplastic material ply onto the tissue ply in a mannersimilar to the process illustrated in FIG. 4. While the thermoplasticmaterial plies can be formed from any of the thermoplastic materialsdescribed above, a preferred material is an isotactic copolymermetallocene polypropylene, wherein the metallocene polypropylenecomprises between about 95 and about 99.95, and preferably between about99.5 and about 99.9 percent by weight of a propylene monomer and betweenabout 0.05 and about 5, and preferably between about 0.1 and about 0.5percent by weight of an ethylene monomer.

The surface of each thermoplastic material ply can range from smooth torough. While the two surfaces can both have similar surfacecharacteristics, in one preferred embodiment, the top surface of the cutresistant layer 60 can be smooth and the bottom surface of the secondtwo ply layers can be rough or have a matte appearance. The method ofcreating these surface effects is well known to those skilled in the artof film production. One method of producing these effects is to use afilm casting roll that mirrors the desired roughness of the film. Forsmooth films, the roll can have a root mean square value of about 0.05to about 5 and for the matte surface the roll can have a root meansquare value of over about 100.

The most preferred resin composition comprises between about 90 andabout 100 percent by weight of the metallocene polypropylene and canfurther include any combination of the following components: an additiveselected from the group of talc, mica, wollastonite, calcium carbonate,barite, glass spheres and fibers, carbon fibers, and ceramic spheres,present in an amount of between about 0 and about 10 percent by weight,a food contact grade alkali metal stearate such as calcium stearate,magnesium stearate and the like or a food contact grade transition metalstearate such as zinc stearate and the like present in an amount ofbetween about 0.01 and about 0.1 percent by weight, and one or moreantioxidants, such as Alvinox P, Irgaphos 168, Alkanox 240, Iraganox3114, Iraganox 1010, Anox IC 14, and Alvinox FB, present in an amount ofbetween about 0 and about 0.25 percent by weight. Small amounts of otheradditives (nucleation agents, clarifiers and pigments) or processingaids can also be included so long as they do not negatively affect theoverall performance properties of the material. Preferably, additivesmust be approved for direct food contact. It is believed that the talcadditive speeds crystalline formation in the polypropylene and improvesthe cut resistant properties of the polymer, whereas a metal stearateserves as a film lubricant for the polypropylene during processing.

The first layer tissue ply 66 and the second layer tissue ply 72 may beprovided by an outside paper provider such as Little Rapids Corporation.Each of the first and second layer tissue plies 66, 72 comprise a virginhardwood and softwood wood pulp present in an amount of between about 90and about 100 percent by weight of the tissue, a polyamide or othersynthetic fiber present in an amount of between about 0 and about 10percent by weight of the tissue ply and can include one or more of thefollowing components in trace amounts: a defoamer, a dryer releaseagent, one or more creping agents, a repulping aid and a bleachneutralizer. The components present in trace amounts are additives whichare used as machine runnability aids for the tissue.

The first layer 60 has a surface area 64 less than the surface area 70of the second layer 62 and is preferably substantially centered on thesecond layer 62. In a preferred embodiment, the first and second layers60, 62 have dimensions such that the surface area 64 of the first layer60 is greater than 50 percent and less than 100 percent of the size ofthe surface area 70 of the second layer 62. An arrangement of layers canbe used wherein first layer 60 is coextensive with the second layer 62in a first dimension but is smaller than the second layer 62 in thesecond dimension. Across the second dimension, the first layer 60 can becentered or offset relative to the second layer 62. When the first layer60 is centered, this forms areas or gutters of similar sizes. Where thefirst layer 60 is offset relative to the second layer 62 in a seconddimension, either a single area or gutter is formed along one edge ortwo different sized areas or gutters can be formed. The visibility ofthat portion of tissue ply 72 of second layer 62 which is not covered byfirst layer 60 provides positive reinforcement to the ultimate user ofthe processing sheet that the sheet has absorbent as well as protectivecharacteristics.

In a commercial embodiment, the substrate may include the first layer 60having dimensions of between about 6 inches (152.4 mm) and about 14inches (355.6 mm) by between about 5 inches (127 mm) and about 10 inches(254 mm) and the second layer 62 may include dimensions of between about10 inches (254 mm) and about 16 inches (406.4 mm) by between about 8inches (203.2 mm) and about 13 inches (330.2 mm). As seen in FIGS. 6 and7, the first layer 60 may have regularly spaced apertures 76 therein topermit flow of fluids therethrough. While a preferred arrangement ofapertures is a zigzag pattern in the first layer 60, wherein theapertures 76 are separated from one another by between about 0.25 inches(6.35 mm) and about 0.375 inches (9.525 mm) in the x-direction andbetween about 0.125 inches (3.175 mm) and about 0.75 inches (19.05 mm)in the y-direction, any arrangement and density of these apertures 76can be used. Alternatively, as shown in FIG. 6 a, the arrangement ofmore numerous apertures 76 may be in an offset row pattern. In such anarrangement, a plurality of straight rows of apertures 76 are offsetfrom each other so that apertures 76 in one row do not line up with theapertures 76 in the adjacent row, thus creating a more condensed zigzagpattern. As shown in FIG. 7, apertures 76 do not extend into or throughthe second layer 62. The apertures 76 are formed by any suitableprocess, such as vacuum, needle or water jet perforation, laser, hotpins or mechanical punching, wherein the apertures 76 have asubstantially circular geometry and a nominal diameter of between about0.060 inches (1.524 mm) and about 0.125 inches (3.175 mm). According tothe dimensions of the first layer 60 and the number of apertures 76therein, the average number of apertures 76 per square inch is betweenabout 0 and about 8. The apertures 76 can further have any othergeometry such as square or rectangular as seen in FIGS. 10 and 11,respectively. Alternatively, the apertures 76 can be oval orellipse-shaped as seen in FIG. 12 or may comprise a series of slots asseen in FIG. 13.

As seen in FIGS. 7 and 8, the first surface area 64 and the portion ofthe second surface area 70 disposed outside of the first surface area 64may be formed with a pattern or texture 78 by embossing, wherein thestep of embossing occurs after the substrate is assembled. This patternor texture of embossing can be seen on a back surface 80 of the secondlayer 62 as seen in FIG. 9.

In another embodiment, any of the above disclosed substrates may bedelivered to the consumer in roll form as seen in FIG. 14 so that theconsumer may cut the product to a desired length and/or shape using acutter bar, scissors, or knife. In a specific embodiment, the roll 98 isprovided in a box (not shown) with a cutter bar and the processingsubstrate is preferably of the type having a top cut resistant layer 100with perforated or punched holes 102, a middle absorbent layer 104, anda bottom barrier layer 106. The top and bottom barrier layers 100 and106 are both made of thermoplastic materials as discussed above.Preferably, but not necessarily, the top and bottom barrier layers 100and 106 are of the same width W1 that defines the width of the roll andthe absorbent layer 104 has width W2 less than the width W1 of the topand bottom barrier layers 100. The layers 100 and 106 are directlysealed together along a length of the roll 98 from the edges of the roll107 up to a point 108 adjacent the absorbent layer 104. The layers 100and 106 are sealed together using a heat seal, a bar seal, adhesive, orany other method known in the art.

Preferably, bands of glue 109 are placed across the width of the roll 98at increments along the roll 98, wherein the glue bands 109 seal thelayers 100 and 106 together at points where the layer 104 isinterrupted. The roll 98 can be cut or torn along any of the bands 109to create a processing substrate of a desired length. If the product iscut or torn along a portion proximate to a center of the glue bands 109,the glue bands 109 form a complete seal 110 around the absorbent layer104 to prevent leakage of fluids out of edges 112 of the processingsubstrate. If desired, the product may have perforations 114 as seen inFIG. 15 preferably located in the center of the glue bands 109 thatallow the consumer to tear off sheets as needed. Alternatively, theproduct may not include glue bands, and one or more perforations may bedisposed at one or more locations and extend through one or more of thelayers 100, 104, and 106.

The processing substrate 120 of FIG. 16 is similar to that of FIG. 7except that the tissue plies 66 and 72 of FIG. 7 are replaced by crepepaper plies 122 and 124 that together form an absorbent layer 125 havingan enhanced absorbency. Specifically, a first layer 126 includes athermoplastic ply 128 disposed above the crepe paper ply 122 whereinholes 130 are formed at spaced locations and extend through at least thethermoplastic ply 128. A second layer 132 includes the crepe paper ply124 disposed above a thermoplastic ply 134. The crepe paper plies 122and 124 provide more space for liquids to be held in the absorbent layer125 of the processing substrate 120. Similarly, as seen in FIG. 17, thetissue plies 66 and 72 may be replaced by plies of a paper materialhaving roughened surfaces 136 and 138 to increase the net thickness andthereby increase the holding capacity of the absorbent layer 125. Theroughened surfaces 136, 138 may be formed by picking or lifting thesurface of paper stock or brushing the paper stock with a wire roll orother suitable device.

In yet another embodiment, as seen in FIG. 18, a bilayer single useprocessing substrate 139 comprises a first two-ply cut-resistant layer140 and a second two-ply layer 142 similar to the embodiment of FIGS.5–9. The first layer 140 has a first surface area 144 and includes abottom ply 146 which may be a hydrophilic material such as tissue, anoleophilic material such as a non-woven polypropylene, or a compositeoleophilic and hydrophilic material commingled normal to the substrate,for example by needle-felting, hydro entanglement, or pneumaticentanglement, and a top thermoplastic cut resistant ply 148. Apertures150 preferably extend through the entire first layer 140, but may extendonly through the top thermoplastic ply 148 of the first layer 140.Optionally, as seen in FIG. 19, a ply 158 which may be a hydrophilicmaterial such as tissue, an oleophilic material such as a non-wovenpolypropylene, or a composite oleophilic and hydrophilic material suchas a needlefelted composite of such materials may be disposed below thebottom ply 146 of the top layer 140. Further, a ply selected from thesame group of materials may be disposed below the top ply 154 of thebottom layer 142.

Other oleophilic materials include THINSULATE® by 3M®, polyester, finelyspun polyolefins, materials coated with clays, or any other knownmaterials, wherein the oleophilic material absorbs oil based liquids,such as grease from fried foods. The second layer 142 has a secondsurface area 152 that is preferably (although not necessarily) largerthan the first surface area 144 and includes a top ply 154 which may bea hydrophilic material such as tissue, an oleophilic material such asthose disclosed above, or a composite oleophilic and hydrophilicmaterial as discussed above, disposed atop a thermoplastic barrier ply156. The thermoplastic material and tissue plies of both layers havethicknesses identical or similar to like layers of FIGS. 5–9. The layer140 may be centered atop the layer 142 and may be adhered or otherwisejoined thereto. It is advantageous in the embodiments of FIGS. 18 and 19to place an oleophilic layer above a hydrophilic layer, but is notnecessary.

Any of the embodiments as disclosed herein may include an odor absorbingmaterial within or applied to one or more of the layers. For example, anodor absorbent compound may be impregnated or otherwise added to eitheror both of the tissue plies, the crepe paper plies, the roughened paperplies or any other portion of the absorbent layer(s) of the processingsubstrate. Suitable odor absorbing materials include baking soda,activated carbon, talc powder, cyclodextrin, ethylenediaminetetra-acetic acid, zeolites, antimicrobial agents, activated silica,activated charcoal, or any other materials known in the art. In order topreserve the odor absorbing capacity of the absorbent layer 170 beforeconsumer use, one or more strips of tape 172 can be attached to the toplayer 174 of the processing substrate 176 as seen in FIG. 20. Thestrip(s) of tape 172 include a relatively low-tack adhesive and coversome or all the holes or apertures 178 in the top layer 174 of theprocessing substrate 176 to keep the substrate 176 from absorbing odorsprior to use. The strip(s) 172 are removed when a consumer is ready touse the processing substrate 176.

Also, any or all of the layers of any of the embodiments disclosedherein may be tinted or otherwise processed to change color when liquidis exposed thereto. For example, the bottom thermoplastic layer of anyof the embodiments presented herein may be tinted almost any color sothat, when the absorbent layer becomes wet and changes from opaque totranslucent or nearly transparent, the color of the thermoplastic layerbelow the absorbent layer will become apparent. A medium tint of anycolor (e.g., purple or blue) works most appropriately because the colorcannot be seen through the absorbent layer when the absorbent layer isdry, but the color can be seen when the absorbent layer is wet.Alternatively, a slighty darker tint of color may be used wherein thecolor can be seen lightly through the absorbent layer when dry, but ismuch darker when the absorbent layer is wet.

Any of the processing substrates as disclosed herein may also include acutthrough indicator as seen in FIG. 21. In a preferred embodiment, aprocessing substrate 192 includes a first two-ply cut-resistant layer194 having a tissue ply 196 disposed below a thermoplastic ply 198. Thefirst two-ply layer 194 is disposed above a second two-ply layer 200that includes a tissue ply 202 disposed above a thermoplastic ply 204,similar to the processing substrate of FIG. 7. The processing substrate192 further includes a tissue layer 206 disposed below the thermoplasticply 204 of the second two-ply layer 200. The tissue layer 206 may be apaper having a basis weight of 20 pounds per 3000 ft², but is preferablya paper having a basis weight of about 10 pounds per 3000 ft². Thethickness of the tissue layer 206 is between about 2 mils and about 6mils thick (0.0508 mm–0.1524 mm). In the event that a user has cutthrough the plies 196, 198, 202, and 204, liquid exuded by the foodbeing cut will be absorbed by the tissue layer 206. This absorption canreadily be seen by the user so that the user can dispose the damagedsubstrate before damage to the underlying surface occurs and/or a messhas been made.

In another modification, the processing substrate shown in any of thepreviously discussed FIGS. can be improved to increase the flow of fluidacross the substrate, thereby allowing for more effective absorption offluids into the absorption layer. For example, in the embodiment seen inFIGS. 6 and 7 the thermoplastic material ply 68 (or any other ply and/orlayer) can be treated with a wetting agent, such as Dow Corning® Q2-5211Superwetting agent. This treatment could be accomplished before, during,or after assembly of the substate layers, and preferably prior toassembly thereof. Alternatively, the thermoplastic material ply 68 (orany other ply and/or layer) could be treated with a hydrophilicadditive, such as Hydrophilic Concentrate VW351 from Polyvel, Inc, ofHammonnton. N.J. Another option is to utilize an anti-fogging agent,such ChemStat AF-1006 from Rutgers Organics of State College, Pa.Preferably, any wetting agent, hydrophilic additive, or anti-foggingagent is of a food grade. In another alternative, the thermoplasticmaterial ply 68 is corona treated (preferably prior to assembly of thelayers), which serves to decrease the surface tension of a liquid on thetop layer 60 so that such liquid readily flows into the absorbentportions of the processing substrate.

The plies and layers of the foregoing embodiments are produced via knownextrusion methods. A first sheet is produced having a cut resistant plyand an absorbent ply. Preferably, the cut resistant ply is treatedbefore the two plies are combined. Referring now to FIG. 22, anapparatus for and method of applying a wetting agent, hydrophilicadditive, or anti-fogging agent 256 to the thermoplastic material ply 68is shown. The ply 68 is extruded by an extrusion apparatus 250 onto achilled casting roller 252. After being chilled by the casting roller252, the ply 68 traverses a path 253 to a pair of nip rollers 254. Spraynozzles 258 disposed along the path 253 spray a wetting agent orhydrophilic additive 256 onto the ply 68. Excess spray from the processcan be collected in a collecting tray 259 and reprocessed. Once the plyis treated, the cut resistant ply and absorbent ply are combined to forma first sheet. A second sheet having a liquid impermeable sheet is thenattached, preferably by an adhesive, to the absorbent ply of the firstsheet. Alternatively, the second sheet also has an absorbent ply and thetwo absorbent plies are attached together.

In an alternative method of application shown in FIG. 23, the ply 68 isimmersed in a liquid bath 260 containing a wetting agent, hydrophilicadditive, or anti-fogging agent 256. Specifically, the ply 68 is removedfrom the casting roller 252 by a pair of nip rollers 254. The pair ofnip rollers 254 directs the ply 68 into the liquid bath 260. Once in theliquid bath 260, the ply 68 is immersed in the wetting agent orhydrophilic additive 256 and contacts secondary rollers 255 that directthe ply through the liquid bath 260 and into a vertical exit path 261.Because the ply 68 exits the liquid bath 260 along the vertical exitpath 261, any excess wetting agent, hydrophilic additive, oranti-fogging agent 256 can easily return to the liquid bath 260.

In yet another embodiment as seen in FIG. 24, a processing substrate 262may include a first layer 264 of a paperboard material and a secondpolymeric layer 266 disposed below the first layer 264 and which isimpervious to liquids. Preferably, although not necessarily, the firstand second layers 264 and 266, respectively, are the same size.

The paperboard material of the first layer 264 preferably, although notnecessarily, has a dry basis weight of at least 150 pounds per 3000 ft²,and more preferably a dry basis weight of at least 200 pounds per 3000ft². Although paper is not inherently cut resistant, high dry basisweight paperboards begin to exhibit some cut resistant properties. Anyof the polymeric materials disclosed above can be used to form thesecond polymeric layer 266, but low density polyethylene andpolypropylene are preferred materials. The thickness and sizes of thefirst and second layers 264 and 266, respectively, are similar toequivalent layers of the embodiments discussed herein.

A still further embodiment utilizes different adhesive patterns toimprove liquid flow from the surface of the substrate. One such adhesivepattern is discussed above in relation to FIGS. 5–9. FIG. 25 illustratesanother adhesive pattern wherein the adhesive lines of FIGS. 5–9extending continuously from side-to side of the first layer 60 arereplaced by discontinuous adhesive segments 300. The adhesive segments300 can be disposed in any regular or irregular (including random)pattern. In the illustrated embodiment, the adhesive segments 300 aresubstantially all of the same length and width and are disposedsubstantially parallel to one another in a regular pattern with theapertures 76 to form alternating rows of apertures 76 and segments 300.Preferably, a regular spacing exists between apertures in an x-directionand a y-direction such that rows of apertures are formed. Alsopreferably, each row of segments 300 is disposed at a locationequidistant to adjacent rows of apertures 76 (except at the top andbottom edges of the layer 60) and each row of apertures 76 is disposedsubstantially equidistant adjacent rows of segments 300 (again, exceptat the top and bottom edges of the layer 60), as seen in FIG. 25. Thus,for example, a first row 303 a comprising a series of segments 300 a1–300 a 23 is disposed in a linear fashion substantially midway betweenrows 301 a and 301 b of apertures 76. Similarly, a second row 303 bcomprising a further series of segments 300 b 1–300 b 24 is disposed ina linear fashion substantially midway between rows 301 b and 301 c ofapertures 76. The segments 300 a 1–300 a 23 are offset fromleft-to-right as seen in FIG. 25 with respect to the segments 300 b1–300 b 24. Preferably, each aperture 76 is disposed above (as seen inFIG. 25) a gap between adjacent ones of the segments 300 in the segmentrow immediately below the aperture 76. In addition, each aperture 76 isdisposed below a midpoint of a segment 300 in the segment rowimmediately above the aperture 76. Each of the segments 300 has aneffective length (i.e., a side-to-side dimension or extent as seen inFIG. 25) less than the width W of the layer 60, and, more preferably,greater than the distance between adjacent segments 300 of each row ofsegments 300. The segment and aperture patterns described above arerepeated over the entire surface area of the layer 60. The combinationof the segment pattern and the aperture pattern results in anadvantageous ready dispersion of liquid into the absorbent plies of theprocessing substrate as discussed above. This advantage of thisembodiment results from the ability of the liquid to flow from anaperture 76 not only between adjacent rows of segments 300, but alsothrough spaces between individual segments 300 of a row.

In an alternative embodiment, the adhesive portions could be applied tothe sheet in continuous lines and then areas of those lines between theadhesive segments 300 may be removed or rendered ineffective as anadhesive prior to securing the layers together. As in the previousembodiment, this results in a processing substrate wherein liquid canflow through the absorbent plies between adhesive segments of the samerow, as well as in the spaces between rows of adhesive segments. Thus,liquid can spread in as many directions as possible from the apertures76.

Also shown in FIG. 25 are two border adhesive strips 304 disposedparallel with and extending the width of the first layer 60. While theborder adhesive strips 304 strengthen the edge bond between layers theyare not a requirement. Also, as shown in FIG. 26, there may be twoadditional border strips extending the length of the first layer 60 toprovide additional strengthening of the layer edge bond.

Referring now to FIGS. 27 and 28, methods for applying the adhesive tothe substrate are shown. The first layer 60 and second layer (not shown)are produced as discussed above. Then the adhesive segments 300 areapplied. In FIG. 27 the adhesive segments 300 are applied to the tissueor liquid absorbent ply 66 of the first layer 60. The application methodincludes the step of using an applicator 310 to deposit regular sizedportions of adhesive onto the first layer 60 at regular intervals. Thesecond layer is then attached to the tissue ply 66. Alternatively, theadhesive could be applied to the second layer in a similar manner andthe layers and can be assembled together.

FIG. 28 shows a different method for applying adhesive. In this methodthe adhesive 301 is applied in continuous strips 312 and then portions302 of the strips 312 are removed or rendered ineffective by a roller316. The roller 316 includes circumferentially spaced lands or ridges318 that extend outwardly from a main roller body 320. The ridges 318are brought into contact with the first layer 60 as the roller 316 isrotated and the strip 312 of adhesive 301 is removed or renderedineffective (i.e., non-flowable and/or non-sticky) where the ridge 318makes contact therewith. This can be accomplished in a variety of ways.In one embodiment, simple contact and/or compression by the ridge 318causes the adhesive to be driven into the absorbent ply of the layeraway from the surface thereof. Alternatively, such contact and/orcompression may cause the adhesive to adhere to the ridge 318 and to beremoved from the first layer 60. The portions may be removed from theridges 318 by cryogenic cleaning using dry carbon dioxide or nitrogen.In a further embodiment, a chemical or other agent carried by the ridgesbonds with the adhesive 301 so that the adhesive is unable to adhere toanother object. This agent could be of an organic or inorganic naturesuch as: talc; a silicon dioxide powder; flour or other starchcomposition; sawdust; paper fibers; a silicone mold release agent; orany anti-stick compounds such as canola oil, cooking sprays, or aTEFLON® agent. In any case, one or more portions 302 of each strip 312are “deactivated” as noted above (i.e., rendered ineffective) so thatwhen the first and second layers are assembled together, the adhesive inthe deactivated zones fails to spread into the absorbent ply of theadjacent layer at such locations, thereby preventing the formation ofliquid impervious zones at the areas where the ridges contacted theadhesive strip. As a result, liquid subsequently applied to thesubstrate liquid can spread out in a substantially radial pattern fromeach aperture.

Any other suitable method of removing or “deactivating” the adhesive canbe used, as desired, to produce one or more discontinuous adhesivesegments each having effective side-to-side dimensions (as seen in FIGS.25 and 26) less than the width of the sheet 60. If desired, as seen inFIGS. 25 and 26, the segments may be separated from one another bydistances less than the lengths of the segments.

As seen in FIGS. 29 and 30, a processing substrate 338 may include anabsorbent material layer 340 and randomly spaced strands of material 342that are substantially continuous and preferably a thermoplasticmaterial disposed on a first side 344 of the absorbent material layer340. The randomly spaced strands 342 preferably provide a top surfacethat is cut resistant and liquid pervious. Almost any type ofthermoplastic material can be used to form the randomly spaced strands342, including but not limited to, polyolefins such as polyethylene andpolypropylene, polyvinyl chloride, polycarbonate, polylactic acid,thermosetting materials, or any type of thermoplastic material with anadditive or filler such as clay. Note that non-thermoplastic materialsare possible, but may not provide the necessary cut resistantproperties. The strands 342 may further be almost any size in diameterranging from about 20 microns to about 4 mm, depending on the use of theprocessing substrate.

The processing substrate 338 may also include a barrier layer 346attached to a second side 348 of the absorbent material layer 340 asseen in FIG. 31. The barrier layer 346 comprises a single polymeric orthermoplastic material ply 350, as discussed in detail above.Alternatively, as seen in FIGS. 32 and 33, the barrier layer 346includes a polymeric or thermoplastic material ply 350 disposed below anabsorbent material ply 352, also discussed in detail above. Further, therandomly spaced strands 342 and absorbent layer have a surface area 354that is smaller than a surface area 356 of the barrier layer 346.

The method of producing the processing substrates of FIGS. 29–33 as seenin FIG. 34 includes the steps of providing the absorbent material layer340 and moving the absorbent material layer 340 in a first direction360. Thereafter, the method includes the step of depositing the randomlyspaced strands of thermoplastic material 342 onto the first side 344 ofthe absorbent material layer 340 to form the necessary surface thereon.As the absorbent material layer 340 moves in the first direction past anextrusion die 362, the randomly spaced strands 342 are deposited throughmultiple spinnerets or small orifices 364 onto the first side 344 of theabsorbent material layer 340. The randomly spaced strands 342 may bedeposited on the entirety of the absorbent material layer 340 or asmaller portion of the absorbent material layer 340 as seen in FIGS. 32and 33.

The extrusion die 362 is fixed relative to the first direction but maymove with respect to a second direction 366 that is perpendicular to thefirst direction. Preferably, the extrusion die 362 rotates andoscillates as it is extruding the strands 342 onto the absorbentmaterial layer 340 to create the randomized pattern of strands 342.Optionally, several extrusion dies 362 may be used at various points inthe path of the moving absorbent material layer 340. Still further, airpressure through the use of pneumatic air devices may be used tomanipulate the division of the strands of material 342.

Thereafter, the randomly spaced strands 342 may optionally be calendaredto form flattened strands with spaces or voids therebetween. This stepcreates a flattened surface and fills in some of the void space betweenstrands 342. Also optionally, a barrier layer 346 may be joined to thesecond side 348 of the absorbent material layer 340 by extrusioncoating, adhesive, or any other process as discussed in detail above. Asalso discussed above, the barrier layer 346 may comprise a singlethermoplastic ply 350, a thermoplastic ply 350 disposed below anabsorbent ply, or any other combination of layers or plies.

Referring now to FIG. 35, an apparatus for producing a sheet materialaccording to a different embodiment is disclosed. An extrusion die 370deposits a thermoplastic resin extrudate onto a chill roll 372. Theoutlet of the extrusion die 370 is profiled and/or the surface of thechill roll 372 is formed such that the resulting layer 400 includesridges 402 and troughs 404 between the ridges 402, as seen in FIG. 36.The thermoplastic resin is selected from the group consisting ofpolyolefins, polyesters, polystyrene, polyvinyl alcohol, polyvinylchloride, nylon, polyacrylonitrile, ABS, ethylvinylacetate, or any othersuitable material. Following extrusion of the first layer 400, a secondlayer 406 of absorbent material is formed in the troughs 404, as seen inFIG. 37.

The absorbent material is selected from the group consisting ofsynthetic or natural fibers or a blend of fibers. These fibers couldconsist of single or multiple strands or could be a combination of acore material (i.e., paper) surrounded by a synthetic outer covering.This absorbent fiber could also be an extruded foam strand. The secondlayer 406 of absorbent material is formed by any suitable apparatus, asis well-known in the art, and would be placed onto the first layer 400of sheet material using the feeding apparatus 407 (FIG. 35).

Thereafter, while the layer 400 is still at least partially molten andpliant, the first layer 400 and the second layer 406 are calendared bycalendaring rollers 408 to compress the ridges 402 so that they foldover to create overhanging portions that hold onto and bind theabsorbent material in the troughs 404. This results in a sheet that hasa back barrier, an absorbent middle portion and a top cut-resistantportion, as seen in FIG. 38. The spacing and size of the ridges 402 canbe selected to optimize cut-resistance and absorbency.

As should be evident from the foregoing, the material forming the firstlayer 400 must be at least somewhat irreversibly deformable (i.e.,pliant) during the calendaring process. This calendaring can beundertaken while the layer 400 is still at least somewhat heated fromthe extrusion process, or the layer 400 may be partially or completelycooled, and then subsequently reheated and calendared in the case ofnon-thermosetting thermoplastic materials. Still further, a material maybe used for the layer 400 that is at least somewhat irreversiblydeformable at lower (i.e., room) temperatures. In this latter case, thecalendaring can be undertaken at any convenient point, as desired.

This manufacturing process produces a cut resistant and fluid absorbentsheet product in a cost-efficient, streamlined manner.

Further specific examples of structures are given below:

Example 1—a trilayer structure wherein the layer 16 comprises 5 mil(0.127 mm) thick PP, filled with up to 40% mica and including 1/32″diameter holes with 9 holes/square inch. The layer 18 is a 37# airlaidcellulose mat thermally laminated to a 5 mil (0.127 mm) thick PP backingsheet comprising layer 20. The layer 16 is thermally bonded to the layer18.

Example 2—a bilayer structure comprising a nonwoven polyolefin fabricupper layer point bonded to a second layer of polymeric film thatfunctions both as a barrier and as a cut resistant surface. Duringmanufacture a food-contact approved surfactant may be applied to theupper layer to provide a desired hydrophilic characteristic.

Example 3—a scrim made of any of a variety of materials, such as athermoplastic or thermosetting polymeric material having voids betweenportions of material is post-filled with absorbent material, such ascellulose, using any suitable post-filling process, such as a wet-laidprocess or a vacuum process, to form a mat. A barrier layer of anysuitable material (e.g., PP or PE) is thereafter applied in any suitablemanner, such as by extrusion lamination, to an undersurface of the matand the mat is thereafter subjected to an embossing process either whilethe barrier layer is still partially molten and/or as heat is applied tocause the barrier layer to bond securely to the scrim.

Example 4—a bilayer single use processing substrate comprises a firstlayer 60, wherein the tissue ply 66 is 2.5 mils (0.0635 mm) thick andthe thermoplastic material ply 68 is 5 mils thick (0.127 mm). The secondlayer 62 has a tissue ply 72 which is 2.5 mils (0.0635 mm) thick and athermoplastic material ply 74 which is 3.5 mils (0.0889 mm) thick,wherein the first layer 60 is secured atop the second layer 62 by anethyl vinyl acetate adhesive.

Each of the thermoplastic material plies consists of a resin comprisingan isotactic copolymer metallocene polypropylene, wherein themetallocene polypropylene comprises 99.9 percent by weight of apropylene monomer and 0.1 percent by weight of an ethylene monomer. Theresin comprises 93.873 percent by weight of the metallocenepolypropylene, 6.050 percent by weight of a talc additive, 0.055 percentby weight of calcium stearate, 0.011 percent by weight of a primaryantioxidant, and 0.011 percent by weight of a secondary antioxidant.

The first and second layer tissue plies 66, 72 comprise 98 percent byweight of a virgin hardwood and softwood wood pulp, 0.2 percent byweight of a polyamide wet strength resin and trace amounts of adefoamer, a dryer release agent, two creping agents, a repulping aid anda bleach neutralizer.

The first layer 60 has dimensions of 9.75 inches (247.65 mm) by 7.688(195.275 mm) inches and the second layer 62 has dimensions of 11.75(298.45 mm) inches by 9.688 inches (246.075 mm). The first layer 60includes 414 regularly spaced apertures created by having a nominaldiameter of 0.08 inches (2.032 mm), wherein the apertures form a zigzagpattern and are separated from one another by 0.279 inches (7.0866 mm)in the x-direction and 0.165 inches (4.191 mm) in the y-direction. Theaverage number of apertures per square inch is 5.52.

The first surface area 64 and the portion of the second surface area 70disposed outside of the first surface area are embossed with embossingpattern 78.

One or more of the following benefits may be obtained, depending uponthe choice of material(s), properties and material amounts:

1. the sheet absorbs food juices while cutting and reduces resultingmess;

2. the sheet is easy to dispose of;

3. the sheet reduces or even prevents accidental germ/microbialcontamination because the germs from one food item will not gettransferred to another if the cutting sheet is disposed of after use;

4. the sheet provides cut resistance, i.e., it helps reduce any cutdamage to the kitchen or other work surface;

5. the sheet does not allow food juices to run all over the worksurface;

6. the sheets may be provided in varying sizes to suit the cutting orother task;

7. the sheet may be used on top of a cutting board or directly on thework surface;

8. the sheet reduces slippage, by providing a skid-resistant contactwith the work surface;

9. after cutting, one need only lift the sides of the sheet to funnelfood into a cooking pot;

10. the sheet can be set on a surface to catch debris and grease;

11. the sheet is easily rolled up with waste captured therein anddisposed of in the trash can;

12. since each sheet is clean the need for repeated cleaning of thecutting board or other work surface is avoided;

13. the sheet can be used to cut or process any food or other materialincluding meat, chicken, fish, soft or hard fruits and vegetables,dough, etc. . . . ;

14. unlike using a paper towel, the sheet does not permit fiber and lintto become attached to the food being cut.;

15. the sheet does not transfer any smell or taste to the product beingcut or otherwise processed (alternatively, the sheet could beimpregnated with a desirable scent, such as lemon, which is thentransferred to the item being processed);

16 the sheet manages bacteria by absorption, containment and barrierrather than by the use of added chemicals;

17. the sheet can be made food contact approved;

18. the top surface reduces slippage of food while cutting;

19. the cutting surface will not dull knives like some hard cuttingsurfaces;

20. the sheet is hygienic;

21. the sheet may be formed with at least one and, preferably multipleabsorbent edges that give an extra measure of security to managebacteria-borne juices;

22. the sheet offers superior food/surface protection for non-cuttingfood preparation applications;

23. the sheet affords an easy, convenient medium for in-home orout-of-home, recreational and outdoor uses;

24. the sheet can be cut by consumers to other sizes and/or shapes;

25. the sheet can be held in place on countertops by a few drops ofwater;

26 the sheet protects the countertop and food from potentially deadlypathogens that cannot be seen;

27 the sheet allows safer food preparation for the consumer and theconsumer's family by reducing the risk of food-borne illness;

28. the sheet can reduce food preparation time;

29 the profile and/or texture of the cutting surface can be customizedto provide benefits not practical in conventional cutting surfaces orboards simply because such articles would be difficult or impossible towash;

30 the sheets do not take up room in the dishwasher or in the bags andwraps drawer of the kitchen;

31. in alternative embodiments bacteria borne liquids are securelytrapped in cells and/or a layer below the cutting surface;

32. the sheet may be constructed so that the consumer can see theabsorption of liquid;

33. the sheet may be made to have a clean hygienic appearance;

34. the sheet may have a decorative appearance that is printed and/orembossed as desired;

35. the sheet absorbs like a paper towel, but has the additionaladvantages of barrier and cut resistance;

36. the sheet has additional uses, for example, as a placemat, ascounter protection for use around stove/cook top, bin/shelf protectionin refrigerator, under dog or cat dish, under plants, under largeserving dishes, etc. . . . ;

37. in some embodiments the sheet has a place to wipe a knife on;

38. the sheet can make a desirable addition to a picnic basket;

39. the sheet can be used to line a refrigerator meat tray;

40. the sheet absorbs and contains all juices from defrosting meat;

41. the sheet can contain odors from foods, such as fish;

42. the sheet can be used on dishes and platters to prevent scratchingof same by knives;

43. the sheet can be placed under sticky and dripping containers inrefrigerator;

44. the sheet does not fall apart like paper towels; and

45. the sheet could be used as a drawer liner or as a mat to do artprojects on.

INDUSTRIAL APPLICABILITY

The present invention encompasses a method and apparatus formanufacturing cut-resistant, absorbent, liquid barrier sheets.

Numerous modifications to the present invention will be apparent tothose skilled in the art in view of the foregoing description.Accordingly, this description is to be construed as illustrative onlyand is presented for the purpose of enabling those skilled in the art tomake and use the invention and to teach the best mode of carrying outsame. The exclusive rights to all modifications which come within thescope of the appended claims are reserved.

1. A disposable cutting sheet for cutting and preparation of food itemsthereon, comprising: a first cut-resistant layer having a plurality ofprojections extending away from troughs disposed between theprojections, wherein the first layer comprises a thermoplastic resin;and a second layer of absorbent material disposed in the troughs andcaptured therein by overhanging portions of the projections.
 2. Thesheet material of claim 1, wherein the thermoplastic resin is selectedfrom the group consisting of polyolefins, polyesters, polystyrene,polyvinyl alcohol, polyvinyl chloride, nylon, polyacrylonitrile,acrylonirile-butadiene-styrene and ethylvinylacetate.
 3. The sheetmaterial of claim 1, wherein the absorbent material is selected from thegroup consisting essentially of non-woven fabrics of synthetic polymersor blends of fibers; laminates of various fabrics or combination offabrics; cellulosic material(s), meltblown and spunbonded nonwovenfabrics, woven fabrics, multiple layers and combinations of fabrics andpapers, absorbent powders including polyacrylic acid polymers,open-celled foams, perforated closed cell foams and/or blends of polymerand cellulosic materials.
 4. A disposable cutting sheet for cutting andpreparation of food items thereon, comprising: a first layer having aplurality of projections with troughs therebetween, wherein the firstlayer comprises a thermoplastic resin; a plurality of absorbent portionsdisposed within each of the troughs, wherein the absorbent portions arecaptured within the troughs by overhanging portions that extend from theprojections of the first layer and wherein the overhanging portions arediscontinuous to allow fluids to migrate from the first material intothe second material.
 5. The sheet material of claim 4, wherein thethermoplastic resin is selected from the group consisting ofpolyolefins, polyesters, polystyrene, polyvinyl alcohol, polyvinylchloride, nylon, polyacrylonitrile, acrylonirile-butadiene-styrene andethylvinylacetate.
 6. The sheet material of claim 4, wherein theabsorbent material is selected from the group consisting essentially ofnon-woven fabrics of synthetic polymers or blends of fibers; laminatesof various fabrics or combination of fabrics; cellulosic material(s),meltblown and spunbonded nonwoven fabrics, woven fabrics, multiplelayers and combinations of fabrics and papers, absorbent powdersincluding polyacrylic acid polymers, open-celled foams, perforatedclosed cell foams and/or blends of polymer and cellulosic materials.